/* ==================== CSS VARIABLES ==================== */
:root {
  /* Colors */
  --bg-primary: #071428;
  --bg-secondary: #0f1724;
  --bg-card: #111827;
  --bg-panel: #0b1220;
  
  --text-primary: #e6eef8;
  --text-muted: #9ca3af;
  
  --accent-blue: #3b82f6;
  --accent-blue-hover: #2563eb;
  --accent-green: #10b981;
  --accent-red: #ef4444;
  --accent-yellow: #f59e0b;
  
  --glass: rgba(255, 255, 255, 0.03);
  --glass-hover: rgba(255, 255, 255, 0.06);
  
  /* Spacing */
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
  --spacing-xl: 32px;
  
  /* Border radius */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 12px;
  
  /* Shadows */
  --shadow-sm: 0 2px 8px rgba(2, 6, 23, 0.4);
  --shadow-md: 0 4px 16px rgba(2, 6, 23, 0.6);
  --shadow-lg: 0 6px 30px rgba(2, 6, 23, 0.7);
  
  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;
  
  /* Font */
  --font-sans: "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

/* ==================== RESET & BASE ==================== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html, body {
  height: 100%;
  margin: 0;
  padding: 0;
  font-family: var(--font-sans);
  background: linear-gradient(180deg, #041022 0%, var(--bg-primary) 60%);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ==================== LAYOUT ==================== */
.app {
  max-width: 1200px;
  margin: 28px auto;
  padding: 22px;
  border-radius: var(--radius-lg);
  background: linear-gradient(180deg, rgba(255,255,255,0.02), rgba(255,255,255,0.01));
  box-shadow: var(--shadow-lg);
  min-height: calc(100vh - 56px);
}

/* ==================== SCREENS ==================== */
.screen {
  display: none;
  animation: fadeIn var(--transition-normal);
}

.screen.active {
  display: block;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ==================== LOADING SCREEN ==================== */
.loading-screen {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--bg-primary);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  z-index: 9999;
}

.loading-spinner {
  width: 48px;
  height: 48px;
  border: 4px solid var(--glass);
  border-top-color: var(--accent-blue);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* ==================== HEADER ==================== */
.main-header {
  margin-bottom: var(--spacing-lg);
  padding-bottom: var(--spacing-md);
  border-bottom: 1px solid var(--glass);
}

.header-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--spacing-md);
}

.header-left h1 {
  font-size: 28px;
  font-weight: 700;
  margin: 0 0 var(--spacing-xs) 0;
}

.tagline {
  color: var(--text-muted);
  font-size: 14px;
  margin: 0;
}

.header-right {
  display: flex;
  gap: var(--spacing-sm);
}

/* ==================== BUTTONS ==================== */
button {
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 600;
  border: none;
  border-radius: var(--radius-md);
  padding: 10px 16px;
  cursor: pointer;
  transition: all var(--transition-fast);
  outline: none;
}

.btn-primary {
  background: var(--accent-blue);
  color: white;
}

.btn-primary:hover {
  background: var(--accent-blue-hover);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3);
}

.btn-ghost {
  background: transparent;
  color: var(--text-muted);
  border: 1px solid rgba(255, 255, 255, 0.06);
}

.btn-ghost:hover {
  background: var(--glass-hover);
  color: var(--text-primary);
  border-color: rgba(255, 255, 255, 0.1);
}

.btn-large {
  padding: 14px 24px;
  font-size: 16px;
}

.btn-block {
  width: 100%;
}

.btn-back {
  background: transparent;
  color: var(--text-muted);
  border: 1px solid var(--glass);
  padding: 8px 12px;
  font-size: 13px;
}

.btn-back:hover {
  background: var(--glass);
  color: var(--text-primary);
}

/* ==================== FORMS ==================== */
input[type="text"],
input[type="number"],
select,
textarea {
  width: 100%;
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  background: var(--glass);
  border: 1px solid rgba(255, 255, 255, 0.06);
  color: var(--text-primary);
  font-size: 14px;
  font-family: var(--font-sans);
  transition: all var(--transition-fast);
}

input:focus,
select:focus,
textarea:focus {
  outline: none;
  border-color: var(--accent-blue);
  background: rgba(59, 130, 246, 0.05);
}

input[type="checkbox"] {
  width: 18px;
  height: 18px;
  cursor: pointer;
}

label {
  display: block;
  font-size: 13px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--spacing-xs);
}

.form-group {
  margin-bottom: var(--spacing-md);
}

.checkbox-group {
  display: flex;
  align-items: flex-start;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-md);
  padding: 12px;
  border-radius: var(--radius-sm);
  background: var(--glass);
}

.checkbox-group input[type="checkbox"] {
  margin-top: 2px;
  flex-shrink: 0;
}

.checkbox-group label {
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.hint {
  font-size: 12px;
  color: var(--text-muted);
  font-weight: 400;
}

/* ==================== FILTERS ==================== */
.filters-section {
  margin-bottom: var(--spacing-lg);
  padding: var(--spacing-md);
  background: var(--bg-panel);
  border-radius: var(--radius-md);
}

.search-box {
  margin-bottom: var(--spacing-md);
}

.search-input {
  font-size: 16px;
  padding: 12px 16px;
}

.filters-row {
  display: flex;
  gap: var(--spacing-md);
  align-items: flex-end;
  flex-wrap: wrap;
}

.filter-group {
  flex: 1;
  min-width: 200px;
}

.filter-select {
  margin-top: var(--spacing-xs);
}

/* ==================== TESTS GRID ==================== */
.tests-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-lg);
}

.test-card {
  background: var(--bg-card);
  border: 1px solid rgba(255, 255, 255, 0.05);
  border-radius: var(--radius-md);
  padding: var(--spacing-lg);
  transition: all var(--transition-normal);
  cursor: pointer;
  display: flex;
  flex-direction: column;
}

.test-card:hover {
  border-color: var(--accent-blue);
  background: rgba(59, 130, 246, 0.03);
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(59, 130, 246, 0.2);
}

.test-icon {
  font-size: 48px;
  margin-bottom: var(--spacing-sm);
}

.test-title {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
  color: var(--text-primary);
}

.test-description {
  font-size: 14px;
  color: var(--text-muted);
  margin-bottom: var(--spacing-md);
  flex-grow: 1;
}

.test-meta {
  display: flex;
  gap: var(--spacing-sm);
  flex-wrap: wrap;
  margin-bottom: var(--spacing-md);
}

.test-tags {
  display: flex;
  gap: var(--spacing-xs);
  flex-wrap: wrap;
  margin-bottom: var(--spacing-md);
}

.tag {
  font-size: 11px;
  padding: 4px 8px;
  border-radius: 4px;
  background: var(--glass);
  color: var(--text-muted);
}

/* ==================== BADGES ==================== */
.badge {
  display: inline-block;
  padding: 6px 10px;
  border-radius: var(--radius-sm);
  background: var(--glass);
  font-size: 12px;
  font-weight: 500;
  color: var(--text-muted);
}

.badge-accent {
  background: rgba(59, 130, 246, 0.1);
  color: var(--accent-blue);
}

.badge-success {
  background: rgba(16, 185, 129, 0.1);
  color: var(--accent-green);
}

.badge-error {
  background: rgba(239, 68, 68, 0.1);
  color: var(--accent-red);
}

.badge-easy {
  background: rgba(16, 185, 129, 0.1);
  color: var(--accent-green);
}

.badge-medium {
  background: rgba(245, 158, 11, 0.1);
  color: var(--accent-yellow);
}

.badge-hard {
  background: rgba(239, 68, 68, 0.1);
  color: var(--accent-red);
}

/* ==================== MODE SELECTION ==================== */
.mode-select-container {
  padding: var(--spacing-lg);
}

.mode-header {
  display: flex;
  align-items: flex-start;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-lg);
}

.mode-header h1 {
  font-size: 28px;
  font-weight: 700;
  margin-bottom: var(--spacing-xs);
}

.mode-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--spacing-md);
}

.mode-card {
  background: var(--bg-card);
  border: 2px solid rgba(255, 255, 255, 0.05);
  border-radius: var(--radius-md);
  padding: var(--spacing-lg);
  text-align: center;
  cursor: pointer;
  transition: all var(--transition-normal);
}

.mode-card:hover {
  border-color: var(--accent-blue);
  background: rgba(59, 130, 246, 0.05);
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(59, 130, 246, 0.2);
}

.mode-icon {
  font-size: 56px;
  margin-bottom: var(--spacing-md);
}

.mode-card h3 {
  font-size: 20px;
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
}

.mode-description {
  font-size: 14px;
  color: var(--text-muted);
  margin-bottom: var(--spacing-md);
  line-height: 1.5;
}

.mode-stats {
  display: flex;
  gap: var(--spacing-sm);
  justify-content: center;
  padding-top: var(--spacing-md);
  border-top: 1px solid rgba(255, 255, 255, 0.05);
}

/* ==================== SETUP ==================== */
.setup-container {
  padding: var(--spacing-lg);
}

.setup-container h2 {
  font-size: 24px;
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
}

.setup-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--spacing-md);
  margin: var(--spacing-lg) 0;
}

.setup-section {
  background: var(--bg-panel);
  padding: var(--spacing-md);
  border-radius: var(--radius-md);
}

.setup-section.full-width {
  grid-column: 1 / -1;
}

.setup-section h3 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: var(--spacing-md);
  padding-bottom: var(--spacing-sm);
  border-bottom: 1px solid var(--glass);
}

.setup-actions {
  display: flex;
  gap: var(--spacing-md);
  margin-top: var(--spacing-lg);
}

.categories-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: var(--spacing-sm);
}

.category-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-sm);
  border-radius: var(--radius-sm);
  background: var(--glass);
}

.category-item label {
  margin: 0;
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  cursor: pointer;
  flex: 1;
}

/* ==================== QUIZ ==================== */
.quiz-container {
  padding: var(--spacing-lg);
}

.quiz-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-md);
}

.meta-left, .meta-right {
  display: flex;
  gap: var(--spacing-sm);
  flex-wrap: wrap;
}

.progress-bar {
  height: 8px;
  background: rgba(255, 255, 255, 0.05);
  border-radius: 10px;
  overflow: hidden;
  margin-bottom: var(--spacing-lg);
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--accent-blue), #60a5fa);
  transition: width var(--transition-normal);
}

.question-card {
  background: var(--bg-card);
  border: 1px solid rgba(255, 255, 255, 0.05);
  border-radius: var(--radius-md);
  padding: var(--spacing-lg);
  box-shadow: var(--shadow-md);
}

.question-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--spacing-md);
  padding-bottom: var(--spacing-sm);
  border-bottom: 1px solid var(--glass);
}

.question-category {
  font-size: 13px;
  font-weight: 600;
  color: var(--accent-blue);
}

.question-difficulty {
  font-size: 12px;
  color: var(--text-muted);
}

.question-text {
  font-size: 20px;
  font-weight: 600;
  margin-bottom: var(--spacing-lg);
  line-height: 1.4;
}

.answers-list {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-md);
}

.answer-btn {
  width: 100%;
  padding: 14px 18px;
  text-align: left;
  background: var(--bg-panel);
  border: 2px solid rgba(255, 255, 255, 0.06);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-size: 15px;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.answer-btn:hover:not(:disabled) {
  border-color: var(--accent-blue);
  background: rgba(59, 130, 246, 0.05);
}

.answer-btn:disabled {
  cursor: not-allowed;
}

.answer-btn.correct {
  border-color: var(--accent-green);
  background: rgba(16, 185, 129, 0.1);
  color: var(--accent-green);
}

.answer-btn.wrong {
  border-color: var(--accent-red);
  background: rgba(239, 68, 68, 0.1);
  color: var(--accent-red);
}

.answer-comment {
  margin-top: var(--spacing-md);
  padding: var(--spacing-md);
  border-radius: var(--radius-md);
  background: rgba(59, 130, 246, 0.05);
  border-left: 4px solid var(--accent-blue);
  display: flex;
  gap: var(--spacing-md);
}

.answer-comment.hidden {
  display: none;
}

.comment-icon {
  font-size: 24px;
  flex-shrink: 0;
}

.comment-text {
  font-size: 14px;
  line-height: 1.6;
  color: var(--text-muted);
}

.question-actions {
  margin-top: var(--spacing-md);
  display: flex;
  justify-content: flex-end;
}

.quiz-actions {
  margin-top: var(--spacing-lg);
  display: flex;
  justify-content: center;
}

/* ==================== RESULTS ==================== */
.results-container {
  padding: var(--spacing-lg);
}

.results-header {
  text-align: center;
  padding: var(--spacing-xl);
  border-radius: var(--radius-md);
  margin-bottom: var(--spacing-lg);
}

.results-header.success {
  background: linear-gradient(135deg, rgba(16, 185, 129, 0.1), rgba(16, 185, 129, 0.05));
  border: 2px solid rgba(16, 185, 129, 0.3);
}

.results-header.fail {
  background: linear-gradient(135deg, rgba(245, 158, 11, 0.1), rgba(245, 158, 11, 0.05));
  border: 2px solid rgba(245, 158, 11, 0.3);
}

.results-icon {
  font-size: 64px;
  margin-bottom: var(--spacing-md);
}

.results-percentage {
  font-size: 72px;
  font-weight: 700;
  margin-bottom: var(--spacing-sm);
}

.results-status {
  font-size: 20px;
  font-weight: 600;
  color: var(--text-muted);
}

.results-stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-lg);
}

.stat-card {
  background: var(--bg-card);
  padding: var(--spacing-lg);
  border-radius: var(--radius-md);
  text-align: center;
  border: 1px solid rgba(255, 255, 255, 0.05);
}

.stat-value {
  font-size: 32px;
  font-weight: 700;
  margin-bottom: var(--spacing-xs);
}

.stat-label {
  font-size: 13px;
  color: var(--text-muted);
}

.results-actions {
  display: flex;
  gap: var(--spacing-md);
  justify-content: center;
  flex-wrap: wrap;
}

/* ==================== ERROR & EMPTY STATES ==================== */
.error-screen,
.empty-state {
  text-align: center;
  padding: var(--spacing-xl);
}

.error-icon,
.empty-icon {
  font-size: 64px;
  margin-bottom: var(--spacing-md);
}

.error-screen h2,
.empty-state h3 {
  font-size: 24px;
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
}

.error-screen p,
.empty-state p {
  color: var(--text-muted);
  margin-bottom: var(--spacing-md);
}

/* ==================== FOOTER ==================== */
.main-footer {
  margin-top: var(--spacing-xl);
  padding-top: var(--spacing-md);
  border-top: 1px solid var(--glass);
}

.footer-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 13px;
  flex-wrap: wrap;
  gap: var(--spacing-md);
}

.footer-left p,
.footer-right p {
  margin: 2px 0;
}

/* ==================== UTILITY CLASSES ==================== */
.hidden {
  display: none !important;
}

.muted {
  color: var(--text-muted);
}

/* ==================== RESPONSIVE ==================== */
@media (max-width: 768px) {
  .app {
    margin: 0;
    padding: var(--spacing-md);
    border-radius: 0;
  }
  
  .header-content {
    flex-direction: column;
    align-items: flex-start;
  }
  
  .header-left h1 {
    font-size: 24px;
  }
  
  .filters-row {
    flex-direction: column;
  }
  
  .tests-grid {
    grid-template-columns: 1fr;
  }
  
  .mode-grid {
    grid-template-columns: 1fr;
  }
  
  .setup-grid {
    grid-template-columns: 1fr;
  }
  
  .results-stats {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .question-text {
    font-size: 18px;
  }
  
  .results-percentage {
    font-size: 56px;
  }
}

@media (max-width: 480px) {
  .results-stats {
    grid-template-columns: 1fr;
  }
  
  .setup-actions,
  .results-actions {
    flex-direction: column;
  }
  
  .btn-block {
    width: 100%;
  }
}

/* ==================== STATISTICS PAGE ==================== */
.stats-header {
  display: flex;
  align-items: flex-start;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-lg);
  padding-bottom: var(--spacing-md);
  border-bottom: 1px solid var(--glass);
}

.stats-header h1 {
  font-size: 28px;
  font-weight: 700;
  margin-bottom: var(--spacing-xs);
}

.global-stats {
  margin-bottom: var(--spacing-xl);
}

.global-stats h2 {
  font-size: 20px;
  font-weight: 600;
  margin-bottom: var(--spacing-md);
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: var(--spacing-md);
}

.stat-card {
  background: var(--bg-card);
  padding: var(--spacing-lg);
  border-radius: var(--radius-md);
  text-align: center;
  border: 1px solid rgba(255, 255, 255, 0.05);
  transition: all var(--transition-normal);
}

.stat-card:hover {
  border-color: rgba(255, 255, 255, 0.1);
  transform: translateY(-2px);
}

.stat-card.success {
  border-color: rgba(16, 185, 129, 0.3);
  background: rgba(16, 185, 129, 0.05);
}

.stat-icon {
  font-size: 32px;
  margin-bottom: var(--spacing-sm);
}

.stat-value {
  font-size: 32px;
  font-weight: 700;
  margin-bottom: var(--spacing-xs);
  color: var(--text-primary);
}

.stat-label {
  font-size: 13px;
  color: var(--text-muted);
}

.tests-stats h2 {
  font-size: 20px;
  font-weight: 600;
  margin-bottom: var(--spacing-md);
}

.test-stat-card {
  background: var(--bg-card);
  border: 1px solid rgba(255, 255, 255, 0.05);
  border-radius: var(--radius-md);
  padding: var(--spacing-lg);
  margin-bottom: var(--spacing-md);
  transition: all var(--transition-normal);
}

.test-stat-card:hover {
  border-color: var(--accent-blue);
  background: rgba(59, 130, 246, 0.03);
}

.test-stat-header {
  display: flex;
  gap: var(--spacing-md);
  align-items: flex-start;
  margin-bottom: var(--spacing-md);
}

.test-stat-icon {
  font-size: 48px;
  flex-shrink: 0;
}

.test-stat-info {
  flex: 1;
}

.test-stat-info h3 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: var(--spacing-xs);
}

.test-stat-meta {
  display: flex;
  gap: var(--spacing-sm);
  flex-wrap: wrap;
}

.progress-bar-large {
  position: relative;
  height: 32px;
  background: rgba(255, 255, 255, 0.05);
  border-radius: var(--radius-md);
  overflow: hidden;
  margin-bottom: var(--spacing-md);
}

.progress-bar-large .progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--accent-blue), #60a5fa);
  transition: width var(--transition-normal);
}

.progress-text {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-size: 14px;
  font-weight: 600;
  color: var(--text-primary);
  text-shadow: 0 0 4px rgba(0, 0, 0, 0.5);
}

.test-stat-actions {
  display: flex;
  gap: var(--spacing-sm);
  flex-wrap: wrap;
}

.btn-sm {
  padding: 8px 12px;
  font-size: 13px;
}

.detailed-stats {
  margin-top: var(--spacing-xl);
  padding-top: var(--spacing-xl);
  border-top: 2px solid var(--glass);
}

.detailed-header {
  display: flex;
  align-items: flex-start;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-lg);
}

.detailed-header h2 {
  font-size: 24px;
  font-weight: 700;
  margin-bottom: var(--spacing-xs);
}

.detailed-content {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xl);
}

.chart-container {
  background: var(--bg-panel);
  padding: var(--spacing-lg);
  border-radius: var(--radius-md);
}

.chart-container h3 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: var(--spacing-md);
}

#historyChart {
  width: 100%;
  height: auto;
  max-width: 100%;
}

.history-section,
.hardest-questions {
  background: var(--bg-panel);
  padding: var(--spacing-lg);
  border-radius: var(--radius-md);
}

.history-section h3,
.hardest-questions h3 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
}

.history-table {
  overflow-x: auto;
  margin-top: var(--spacing-md);
}

table {
  width: 100%;
  border-collapse: collapse;
}

th, td {
  padding: 12px;
  text-align: left;
  border-bottom: 1px solid var(--glass);
}

th {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-primary);
  background: rgba(255, 255, 255, 0.02);
}

td {
  font-size: 14px;
  color: var(--text-muted);
}

tr:hover td {
  background: rgba(255, 255, 255, 0.02);
}

.question-text-cell {
  max-width: 400px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

/* ==================== RESPONSIVE STATS ==================== */
@media (max-width: 768px) {
  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .test-stat-header {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }
  
  .test-stat-actions {
    flex-direction: column;
  }
  
  .btn-sm {
    width: 100%;
  }
  
  .question-text-cell {
    max-width: 200px;
  }
}

@media (max-width: 480px) {
  .stats-grid {
    grid-template-columns: 1fr;
  }
  
  .stat-icon {
    font-size: 24px;
  }
  
  .stat-value {
    font-size: 24px;
  }
}

/* ==================== SETTINGS PAGE ==================== */
.settings-header {
  display: flex;
  align-items: flex-start;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-lg);
  padding-bottom: var(--spacing-md);
  border-bottom: 1px solid var(--glass);
}

.settings-header h1 {
  font-size: 28px;
  font-weight: 700;
  margin-bottom: var(--spacing-xs);
}

.settings-container {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xl);
}

.settings-section {
  background: var(--bg-card);
  border: 1px solid rgba(255, 255, 255, 0.05);
  border-radius: var(--radius-md);
  padding: var(--spacing-lg);
}

.settings-section h2 {
  font-size: 20px;
  font-weight: 600;
  margin-bottom: var(--spacing-lg);
  padding-bottom: var(--spacing-sm);
  border-bottom: 1px solid var(--glass);
}

.settings-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--spacing-md);
  padding: var(--spacing-md);
  border-radius: var(--radius-sm);
  background: var(--bg-panel);
  margin-bottom: var(--spacing-md);
}

.settings-item.danger {
  border: 1px solid rgba(239, 68, 68, 0.2);
  background: rgba(239, 68, 68, 0.03);
}

.settings-item-info h3 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 4px;
}

.settings-item-info p {
  font-size: 13px;
  margin: 0;
}

.settings-item-value,
.settings-item-action {
  flex-shrink: 0;
}

.storage-info {
  min-width: 200px;
}

.storage-bar {
  height: 8px;
  background: rgba(255, 255, 255, 0.05);
  border-radius: 10px;
  overflow: hidden;
  margin-bottom: var(--spacing-xs);
}

.storage-fill {
  height: 100%;
  border-radius: 10px;
  transition: width var(--transition-normal);
}

.storage-text {
  font-size: 13px;
  color: var(--text-muted);
  text-align: right;
}

.btn-danger {
  color: var(--accent-red);
  border-color: rgba(239, 68, 68, 0.3);
}

.btn-danger:hover {
  background: rgba(239, 68, 68, 0.1);
  border-color: var(--accent-red);
  color: var(--accent-red);
}

.about-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-lg);
}

.about-item {
  background: var(--bg-panel);
  padding: var(--spacing-md);
  border-radius: var(--radius-sm);
}

.about-label {
  font-size: 12px;
  color: var(--text-muted);
  margin-bottom: 4px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.about-value {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-primary);
}

.about-description {
  margin-bottom: var(--spacing-lg);
  line-height: 1.6;
}

.about-description p {
  margin-bottom: var(--spacing-sm);
}

.about-links {
  display: flex;
  gap: var(--spacing-sm);
  flex-wrap: wrap;
}

.about-links a {
  text-decoration: none;
}

/* ==================== MODAL ==================== */
.modal {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(7, 20, 40, 0.9);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 9999;
  backdrop-filter: blur(4px);
}

.modal.hidden {
  display: none;
}

.modal-content {
  background: var(--bg-card);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-lg);
  max-width: 600px;
  width: 90%;
  max-height: 80vh;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
}

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-lg);
  border-bottom: 1px solid var(--glass);
}

.modal-header h2 {
  font-size: 20px;
  font-weight: 600;
  margin: 0;
}

.modal-close {
  background: transparent;
  border: none;
  color: var(--text-muted);
  font-size: 24px;
  cursor: pointer;
  padding: 0;
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 4px;
  transition: all var(--transition-fast);
}

.modal-close:hover {
  background: var(--glass);
  color: var(--text-primary);
}

.modal-body {
  padding: var(--spacing-lg);
  overflow-y: auto;
}

.changelog-entry {
  margin-bottom: var(--spacing-lg);
  padding-bottom: var(--spacing-lg);
  border-bottom: 1px solid var(--glass);
}

.changelog-entry:last-child {
  border-bottom: none;
  margin-bottom: 0;
}

.changelog-entry h3 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 4px;
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.changelog-entry p {
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: var(--spacing-md);
}

.changelog-entry ul {
  margin: 0;
  padding-left: 20px;
}

.changelog-entry li {
  font-size: 14px;
  line-height: 1.6;
  margin-bottom: 6px;
  color: var(--text-muted);
}

/* ==================== RESPONSIVE SETTINGS ==================== */
@media (max-width: 768px) {
  .settings-item {
    flex-direction: column;
    align-items: flex-start;
  }
  
  .settings-item-action {
    width: 100%;
  }
  
  .settings-item-action button {
    width: 100%;
  }
  
  .storage-info {
    width: 100%;
  }
  
  .about-grid {
    grid-template-columns: 1fr;
  }
}

/* ==================== FLASHCARD MODE ==================== */
.flashcard-container {
  width: 100%;
  max-width: 700px;
  margin: 0 auto;
  padding: var(--spacing-md);
}

.flashcard-container.with-animation {
  perspective: 1200px;
}

.flashcard {
  position: relative;
  width: 100%;
  min-height: 500px;
  transition: transform 0.6s;
  transform-style: preserve-3d;
}

.flashcard.flipped {
  transform: rotateY(180deg);
}

.flashcard-side {
  position: absolute;
  width: 100%;
  min-height: 500px;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  background: var(--bg-card);
  border: 2px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-lg);
  padding: var(--spacing-xl);
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
}

.flashcard-front {
  z-index: 2;
}

.flashcard-back {
  transform: rotateY(180deg);
  display: none;
}

.flashcard.flipped .flashcard-back {
  display: block;
}

.flashcard-content {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
  height: 100%;
}

.flashcard-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-bottom: var(--spacing-sm);
  border-bottom: 1px solid var(--glass);
}

.flashcard-question {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: var(--spacing-xl) 0;
}

.flashcard-question h2 {
  font-size: 28px;
  font-weight: 600;
  line-height: 1.4;
  color: var(--text-primary);
}

.flashcard-hint {
  text-align: center;
  padding: var(--spacing-md);
  background: rgba(59, 130, 246, 0.05);
  border-radius: var(--radius-md);
  border: 1px dashed rgba(59, 130, 246, 0.3);
}

.flashcard-hint p {
  margin: 0;
  font-size: 14px;
}

.flashcard-action {
  text-align: center;
  padding-top: var(--spacing-md);
}

.btn-large {
  padding: var(--spacing-md) var(--spacing-xl);
  font-size: 16px;
  font-weight: 600;
  min-width: 200px;
}

/* Зворотня сторона */
.flashcard-question-small {
  background: var(--bg-panel);
  padding: var(--spacing-md);
  border-radius: var(--radius-sm);
  border-left: 3px solid rgba(156, 163, 175, 0.3);
}

.flashcard-question-small strong {
  font-size: 12px;
  text-transform: uppercase;
  color: var(--text-muted);
  letter-spacing: 0.5px;
}

.flashcard-question-small p {
  margin: var(--spacing-xs) 0 0 0;
  font-size: 14px;
  color: var(--text-muted);
}

.flashcard-answer {
  background: rgba(16, 185, 129, 0.05);
  border: 2px solid rgba(16, 185, 129, 0.3);
  border-radius: var(--radius-md);
  padding: var(--spacing-lg);
}

.flashcard-answer h3 {
  font-size: 16px;
  font-weight: 600;
  color: var(--accent-green);
  margin-bottom: var(--spacing-sm);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.flashcard-answer p {
  font-size: 18px;
  line-height: 1.6;
  color: var(--text-primary);
  margin: 0;
}

.flashcard-comment {
  background: rgba(59, 130, 246, 0.05);
  border-left: 3px solid var(--accent-blue);
  padding: var(--spacing-md);
  border-radius: var(--radius-sm);
}

.flashcard-comment p {
  margin: 0;
  font-size: 14px;
  line-height: 1.5;
}

.flashcard-separator {
  height: 1px;
  background: linear-gradient(
    to right,
    transparent,
    var(--glass),
    transparent
  );
  margin: var(--spacing-md) 0;
}

.flashcard-self-check {
  text-align: center;
}

.flashcard-self-check h4 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: var(--spacing-md);
  color: var(--text-primary);
}

.self-check-buttons {
  display: flex;
  gap: var(--spacing-md);
  justify-content: center;
}

.self-check-buttons button {
  flex: 1;
  max-width: 200px;
}

.btn-success {
  background: rgba(16, 185, 129, 0.15);
  border: 2px solid var(--accent-green);
  color: var(--accent-green);
}

.btn-success:hover {
  background: rgba(16, 185, 129, 0.25);
  border-color: var(--accent-green);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(16, 185, 129, 0.3);
}

.btn-error {
  background: rgba(239, 68, 68, 0.15);
  border: 2px solid var(--accent-red);
  color: var(--accent-red);
}

.btn-error:hover {
  background: rgba(239, 68, 68, 0.25);
  border-color: var(--accent-red);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(239, 68, 68, 0.3);
}

/* Анімація появи */
@keyframes fadeInScale {
  from {
    opacity: 0;
    transform: scale(0.95);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

.flashcard-side {
  animation: fadeInScale 0.3s ease-out;
}

/* Без анімації - просте відображення */
.flashcard-container:not(.with-animation) .flashcard {
  transform: none !important;
}

.flashcard-container:not(.with-animation) .flashcard-back {
  position: relative;
  transform: none !important;
}

/* ==================== RESPONSIVE FLASHCARD ==================== */
@media (max-width: 768px) {
  .flashcard-question h2 {
    font-size: 22px;
  }
  
  .flashcard-answer p {
    font-size: 16px;
  }
  
  .flashcard-side {
    min-height: 450px;
    padding: var(--spacing-lg);
  }
  
  .self-check-buttons {
    flex-direction: column;
  }
  
  .self-check-buttons button {
    max-width: 100%;
  }
}

@media (max-width: 480px) {
  .flashcard-container {
    padding: var(--spacing-sm);
  }
  
  .flashcard-question h2 {
    font-size: 20px;
  }
  
  .flashcard-side {
    min-height: 400px;
    padding: var(--spacing-md);
  }
  
  .btn-large {
    min-width: 150px;
    font-size: 14px;
    padding: var(--spacing-sm) var(--spacing-lg);
  }

    /*
  * СТИЛІ ДЛЯ MATCHING PLUGIN
  */

  .matching-task-area {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  position: relative;
  isolation: isolate;
}

  .matching-column {
  flex: 0 0 45%;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

  .matching-item {
  border: none;
  border-radius: 10px;
  padding: 10px 14px;
  font-size: 16px;
  text-align: left;
  background: #fff;
  cursor: pointer;
  transition: 0.2s;
}

.matching-item:hover {
  transform: scale(1.03);
}

  /* 1. Кольоровий фон для ПИТАННЯ */
  .question-item {
      /* Використовуємо CSS-змінну --item-color з JS */
      border-left: 5px solid var(--item-color, #ccc);
      box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
  }

  /* 2. Активний вибір (Перший клік) */
  .active-select {
      border-color: #f1c40f; /* Жовтий */
      box-shadow: 0 0 0 3px #f1c40f44;
  }

  /* 3. Конекшн-шар (SVG) */
  .connection-layer {
  position: absolute;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  overflow: visible;
  background: transparent !important;   /* <— ось головне */
  mix-blend-mode: normal !important;    /* не дозволяє сіре змішування */
}

  /* 4. Фінальна валідація */
  .matching-item.correct {
      background-color: #2ecc7144; /* Зелений з прозорістю */
      border-color: #2ecc71;
      color: #1a7f37;
  }

  .matching-item.wrong {
      background-color: #e74c3c44; /* Червоний з прозорістю */
      border-color: #e74c3c;
      color: #962828;
  }

  /* 5. Стилі для ліній SVG */
  .connection-layer line {
      transition: all 0.2s; /* Для плавного переходу кольорів */
  }
}